Retractable Cutting and Pulling Tool with Uphole Milling Capability
Cutter blades extend and stay extended as long as pressure on a piston is continued. The blades either open fully in open hole or cut through the wall of a tubular and then mill in an uphole direction to take out a piece of the tubular. The piston that held out the blades when pressure was applied is acted on by a return bias when the pressure is removed so that the blades can retract and the tool removed through the cut tubular. As a backup a plug can be dropped to obstruct a through passage in the piston so that pressure from the surface can be used to force the piston back to retract the blades. Continued drilling operations or the cut and milled portion can be then blocked off such as with cement for a plug and abandonment of the well.
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This application is a continuation-in-part of U.S. patent application Ser. No. 13/645,118, for “Cutting and Pulling Tool with Double Acting Hydraulic Piston”, published as U.S. 2014-0096947-A1, filed on Oct. 4, 2012, and claims the benefit of priority from the aforementioned application.
FIELD OF THE INVENTIONThe field of the invention is cutting a pulling tools and more particularly tools that extend a cutter blade by rotation about a fixed pivot location to a flush support for the blade in an extended position so that the string above the cut can milled in an uphole direction to allow continuous drilling operation without restriction.
BACKGROUND OF THE INVENTIONCutting tools in the past were run with spears so that the cut tubular string could be retained by the spear and then pulled out of the hole. The cutter designs were variable and many included blades that extend by sliding down a ramp and turning about a pivot that was driven by a piston that was fluid driven and a spring to retract the blades. Some examples of such designs are U.S. Pat. Nos. 5,791,409; 2,136,518; 2,167,739 and U.S.2013/0168076. As to the latter reference, there is no pivoting action as the blades translate radially. With this orientation, the blades have to either extend out below a tubular to be milled or into a recess where another tool has already removed a tubular wall. The illustrated tool is not designed to cut through a wall of a tubular due to its blade orientation. Other styles for cutting tubular strings are illustrated in U.S. Pat. Nos. 7,823,632; 5,018,580; 4,856,642 and 5,014,780.
In the original version of the present invention several issues in the prior design are addressed and a design is presented that is a more reliable and economical. The actuating piston is flow actuated to shift and extend the cutting blades and to retain the extended blade position even after the flow is cut off. The blades are retracted with pressure on a landed plug on the piston so that a return spring is not required. The reverse movement of the piston shears out the body lock ring that had previously held the piston on the blade extended position. When the blades get through the wall of the tubular string being cut the adjacent housing squarely supports the blades that are extended radially so as to better support the cut string with reduced stress on the blades as the cut string is raised up to the point where it can be supported from slips on the rig floor so that the blades can be retracted after slacking off weight and pressuring up against a bumped plug on top of the piston.
As currently envisioned, the cutter blades extend and stay extended as long as pressure on a piston is continued. Instead of cutting off a transition in a tubular that had been expanded and removing the transition to the surface, the blades cut through the wall of a tubular and then mill in an uphole direction to take out a piece of the tubular. The piston that held out the blades when pressure was applied is acted on by a return bias when the pressure is removed so that the blades can retract and the tool removed through the cut tubular. As a backup a plug can be dropped to obstruct a through passage in the piston so that pressure from the surface can be used to force the piston back to retract the blades. In one possible use of the tool, the cut and milled portion can be then blocked off such as with cement for a plug and abandonment of the well.
These and other features will be more readily apparent to those skilled in the art from a review of the description of the preferred embodiment and the associated drawings while recognizing that the full scope of the invention is to be found in the appended claims.
SUMMARY OF THE INVENTIONCutter blades extend and stay extended as long as pressure on a piston is continued. Instead of cutting off a transition in a tubular that had been expanded and removing the transition to the surface, the blades cut through the wall of a tubular and then mill in an uphole direction to take out a piece of the tubular. The piston that held out the blades when pressure was applied is acted on by a return bias when the pressure is removed so that the blades can retract and the tool removed through the cut tubular. As a backup a plug can be dropped to obstruct a through passage in the piston so that pressure from the surface can be used to force the piston back to retract the blades. In one possible use of the tool, the cut and milled portion can be then blocked off such as with cement for a plug and abandonment of the well.
The cutting and pulling tool 10 has a top sub 12 with thread 14 to which is attached a work string that is not shown that extends to a well surface also not shown. Below the top sub 12 is a body 16 that has a centralizer assembly 18 on the outside and a piston assembly 20 internally in passage 22 that starts at thread 14 and continues into the bottom sub 24. Additional tools can be attached at thread 26 as needed.
A plurality of pivoting blade assemblies 28 are preferably arranged at 120 degree spacing for a total of three although other spacing and blade counts can be used. Each blade assembly has a fixed pivot axis about a pin 30. Each blade has an arcuate cutting edge 32 with opposed parallel surfaces 34 and 36 flanking the cutting edge 32 as better seen in
It should be noted that in the preferred application the blade assemblies 28 are actuated outwardly in a larger tubular portion 50 that has been expanded relative to the unexpanded portion 52 that is above with a transition 54 in between which is where the cut is to take place. As shown in
Once the
Those skilled in the art will appreciate the various advantages of the above invention. The piston is actuated with fluid flow to extend the blades but the flow need not be maintained to keep the blades extended as a lock ring selectively holds the blades extended to make the cut. There is no return spring. Reverse piston movement occurs preferably with a dropped plug into the passage in the piston followed by pressuring up to break the shear pin or pins on the lock ring or rings so that the blade assemblies are retracted with piston movement in the downhole direction. By the time the blade assemblies finish the cut the blades are extended approximately 90 degrees to the axis of the tool so that the severed tubular string lands squarely on a radially oriented surface while the window associated with each blade assembly has a radial bottom surface on which a flat surface on the blade assembly bottoms lands so that the loading on the blade assemblies is in the axial direction with little if any radial loading component.
A variation of the above described tool is contemplated. The items 60, 62 and 64 are removed and replaced with a spring 80 acting on the piston 20′ that is braced off of housing 16 using a shoulder 82 and a spring stop washer 84. The impact of this change is that the piston does not lock in the
The above description is illustrative of the preferred embodiment and many modifications may be made by those skilled in the art without departing from the invention whose scope is to be determined from the literal and equivalent scope of the claims below:
Claims
1. A cut and tubular sectioning apparatus for a subterranean tubular comprising:
- a mandrel having a mandrel passage therethrough;
- a piston movably mounted to said mandrel;
- at least one blade assembly hydraulically responsive to piston movement for pivoting extension and retraction with respect to the subterranean tubular for respectively cutting through a wall of the tubular and sectioning the tubular in an uphole direction and removal of the apparatus.
2. The apparatus of claim 1, wherein:
- said piston has a passage therethrough and is driven in a first direction for extension of said blade assembly by flow through said passage.
3. The apparatus of claim 2, wherein:
- reduction of said flow allows said piston to move in a second direction opposite said first direction for removal through the tubular being cut.
4. The apparatus of claim 1, wherein:
- said piston is moved in a first direction so that said blade assembly is extended by flow through a piston passage that is in flow communication with said mandrel passage, said mandrel further comprising a flow restriction to create back pressure against a lower end of said piston.
5. The apparatus of claim 1, wherein:
- said blade assembly pivots about a stationary pivot location on said mandrel.
6. The apparatus of claim 3, wherein:
- said piston is biased in said second direction.
7. The apparatus of claim 1, wherein:
- said piston is driven in a reverse direction than flow that passes through a piston passage for extension of said blade assembly.
8. The apparatus of claim 1, wherein:
- said piston comprises a piston passage that is selectively obstructed so that pressure on said piston with said piston passage obstructed retracts said blade assembly.
9. The apparatus of claim 1, wherein:
- said mandrel further comprises a centralizer.
10. The apparatus of claim 6, wherein:
- said bias is provided by a mechanical or fluid spring.
11. The apparatus of claim 10, wherein:
- said piston is moved in a first direction so that said blade assembly is extended by flow through a piston passage that is in flow communication with said mandrel passage, said mandrel further comprising a flow restriction to create back pressure against a lower end of said piston.
12. The apparatus of claim 11, wherein:
- said blade assembly pivots about a stationary pivot location on said mandrel.
13. The apparatus of claim 12, wherein:
- said piston is driven in a reverse direction than flow that passes through said piston passage for extension of said blade assembly.
14. The apparatus of claim 13, wherein:
- said piston passage is selectively obstructed so that pressure on said piston with said piston passage obstructed retracts said blade assembly.
15. The apparatus of claim 14, wherein:
- said mandrel further comprises a centralizer.
17. The apparatus of claim 8, wherein:
- said passage is selectively obstructed by a dart that lands on a seat surrounding said piston passage.
18. The apparatus of claim 14, wherein:
- said passage is selectively obstructed by a dart that lands on a seat surrounding said piston passage.
19. The apparatus of claim 10, wherein:
- said mechanical spring comprises a coiled spring or a stack of Belleville washers.
20. The apparatus of claim 1, wherein:
- said blade assembly comprises blades having a top surface cutting structure that when extended facilitate sectioning the tubular in an uphole direction.
Type: Application
Filed: Oct 2, 2014
Publication Date: May 14, 2015
Patent Grant number: 9725977
Applicant: BAKER HUGHES INCORPORATED (Houston, TX)
Inventors: Mary L. Laird (Madisonville, LA), Robbie B. Colbert (Perdido, AL)
Application Number: 14/504,995
International Classification: E21B 29/00 (20060101); E21B 17/10 (20060101);